Chemical modification of poly(epichlorohydrin) with phenolate. Studies of the side reactions

Gold‐Catalyzed Intermolecular Addition of Carbonyl Compounds to 1,6‐Enynes: Reactivity, Scope, and Mechanistic Aspects

“…The major drawback of the nucleophilic displacement of the PECH chlorine atom is the dehydrochlorination side reaction and the fact that the resulting vinylether units degrade the polymer 31, 38, 39. These competitive reactions related to the basicity of the nucleophile seem to play a significant role for phenolates but are negligible in aromatic carboxylates, as can be seen here.…”

“…The same carbon of the chain in position 4 appears downfield at 73.3 ppm. Neither 1 H NMR nor 13 C NMR spectra determined any of the signals corresponding to unsaturated vinylether units38 in detectable amounts, indicating that the deshydrohalogenation reaction does not take place under our experimental conditions.…”

“…However, Ujiie50 claimed for the quantitative modification of PECH of different molecular weights ( M n = 2800–110,000) with mesogenic phenolates, but the extent of the reaction was fixed only on the basis of the absence of CH 2 Cl signals in FTIR and 13 C NMR. We demonstrated38 that under these conditions extensive deshydrohalogenation occurs so the actual modification achieved is unclear.…”

Liquid crystalline polyamines containing side dendrons: Toward the building of ion channels based on polyamines

“…Since we obtained good modification degrees and detected no dehydrochlorination side reactions in the chemical modification of PECH [12,13], we were encouraged to use the same strategy and reaction conditions also for poly(epichlorohydrin-co-ethylene oxide) [P(ECH-co-EO)]. In a very recent paper [14], we have reported the preparation of a new family of liquid crystalline columnar polyethers by chemically modifying P(ECH-co-EO) with the dendron 3,4,5-tris[4-(n-dodecan-1-yloxy) benzyloxy]benzoate under different conditions.…”

Synthesis of 5-Azacastanospermine, a Conformationally Restricted Azafagomine Analogue

“…The chemical modification of PECH under phase‐transfer catalyst conditions with carboxylates has been used by several researchers [25, 26], but few studies have focused on obtaining anisotropic materials [27, 28]. Because we obtained good modification degrees and detected no dehydrochlorination side reactions in the chemical modification of PECH [29, 30], we were encouraged to use the same strategy and reaction conditions for chemically modifying P(ECH‐ co ‐EO). The given reactions were performed for 8 days in different solvents like THF, THF/DMF, and NMP.…”